Pre-exposure prophylaxis (PrEP) to prevent HIV infection with anti-retroviral (ARV) medications was found to be partially efficacious among men who have sex with men (MSM) [1] and heterosexuals [2],[3]. Other studies have provided information about potential uptake of PrEP among MSM, including factors associated with use and sharing of HIV medications before [4]and after [5] ARV efficacy was known. In a study of high-risk, substance-using MSM in four United States cities conducted prior to the release of efficacy trial results, black and Latino (versus white) MSM were more willing to use a less effective PrEP product in order to avoid condom use [6]; further, high-risk MSM with less education reported more non-prescribed, pre-efficacy ARV use (by HIV-negative men) and sharing of ARVs with sex partners (by HIV-positive men) to prevent HIV infection [4]. In an Internet study of US MSM immediately following release of the efficacy trial results among MSM, black and Latino (versus white) MSM were more willing to use PrEP after efficacy was known [5].

Colleagues [7]–[9] have identified important challenges relating to the implementation of PrEP, including specialist and generalist physician willingness to prescribe PrEP based on trial results [10]. These issues will become even more prominent due to the recent recommendation of the US Food and Drug Administration (FDA) Advisory Committee to approve emtricitabine/tenofovir disoproxil fumarate (TDF/FTC or Truvada) for use as PrEP among sexually active adult men and women. This essay addresses PrEP implementation challenges for MSM and their communities in the US.